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LED Light Bottle Design Challenge

Millions of people around the world live in darkness without access to lightbulbs and power. Within dense city-slums, windows are few and far between so people often open up a skylight in the roof to allow light in. A clever trick has been to place a 2L Bottle with water to disperse light and a little bleach to discourage microbial growth. Yet what about nighttime? What then? Perhaps an even better solution is a waterproof LED within the bottle, connected to a small solar panel and a battery system.

We have 4 LEDs, a single 7.5V 220mA Solar Panel, two NiHm batteries and a 2L Coke bottle. Using these components, design the casing for the LEDs so it can be inserted into the bottle, as well as the case for the panels and batteries. The designs will be made by our custom 3D Printer, a massive machine measuring 600 mm x 400 mm x 600 mm which uses similar extrusion techniques to the Makerbot.

Prizes

1st Prize

$300 for the Best Design + GrabCAD TShirt

2nd Prize

$100 for the second-best design + GrabCAD TShirt

The "For Being Awesome" Prize

$100 +GrabCAD TShirt to the most active and helpful member - you're sharing advice with everyone and rendering other people's work (and maybe uploading CAD models of the batteries and solar panel for everybody to use).

About the jury?

JF Brandon and Gabe Blanchet

About EN3D

Aims to use 3D Printing and Crowdsourcing to develop designs to improve the lives of people in lesser developed countries. Crowdsourcing through GrabCAD is a powerful way for thousands of Engineers and Designers to come up with great ideas. 3D Printing is now an affordable way to produce complex designs, on demand, using only what is needed in small quantities.

Battery for led light bottle design challengeThis is the battery provided in the specifications in a few different file formats. What type of battery is it? Is this the battery that we must use or can it be a different battery?

@Stephen Nyberg You rock sir. Unconditionally. Now, the batteries are NiMh ... I spec'd the battery size so that you could design the housing accordingly.
Thanks for putting up the files in different formats :)
To all the rest - the water is in the bottle to better disperse the light. Think of a hole in a roof...it only allows light in the direction from the sun. However, when it passes through water, it is more evenly distributed, regardless of the direction of the sun.

@Vincenzo Ricci - Thats an interesting question....you could put the lights on the outside, but that blocks the sun coming in during the day. If the LED is on the inside, that means more daylight is coming in...

Hi JF, I thought I had to move the leds outside of the bottle, but in a location that does not block the light, or in small part, even inside the system would block some light; this choice, however, would only work with the model bottle of coke, because this has indentations , but reduce in part the problem of resistance to water

I thought I saw a comment that my LED was 5m and not 5mm but I don't see it anymore. I just checked it and I think it is correct (the diameter of the LED is 5mm in the sldprt file). As far as the battery and solar panel goes I just used the provided STL and added a few more file formats. I think they are all correct but if someone finds and error please let me know.

Do we have to create a new cap or can we incorporate an existing cap? I wasn't sure if the recycled bottles they are using have caps. Printing could be simplified if we could just use the cap that came with the bottle (at least in the idea I have).

@Stephen I suppose you could use the original cap - you could say 'drill a hole this big and insert the two parts through it.' .... but it has to be a sealed design .... it might be easier to design an integrated cap system....
Or you can do both :)

can i upload two designs? one design fits exact to the requirements while the other is slightly different but still accomplishes what the requirements want from me.
regarding the solar-panel plastic case. It has to be only attachable to the roof (using screws) or can there be an alternative way to attach it?
regarding waterproofing. are we allowed to use some sort of sealant like silicone when installing the components in the plastic case and cap case?

one final question:
the 3d printer can't print clear see-through materials right? so this means that the led heads will be sort of exposed out of the casing right? so lets say the silicone (if allowed) would prevent water from entering the cap case. what about the led light itself, is it water proof? because from the pictures i see that the bottle is filled with water so i am guessing the cap case and the led's might be submerged in water once screwed onto the bottle.

@ comed... really? okay if thats the case then what about the texture (finish) of the surface? i'm not an expert but the reason why i asked this is because i have my doubts on the texture of the 3d print plastic (eg. makerbot). pictures of it look rough and... wavy...
lets say i have a dome inside which the led lights are set. the dome is facing down at the bottom of the 2l cola bottle. now if the surface of the dome (both inner and outer surface) is imperfect the light would not effectively exit the dome right and hence not light up the bottle effectively. i don't know the technical term but i think this would have something to do with refraction or reflection of the light when entering and exiting the dome shaped see-through plastic right?

Well, I just googled that before I started my work, and I found it on a site, but I dont have any experience with 3D printing. What I think, that is doesnt matter if the furfaces are rough, becouse the light is "homogenized" by the surrounding water, and the light will enter the water.

@Ibrahim Sanih Ahmed - You can submit as many design as you want. The LEDs will be submerged to the top of the bottle...the bottom of them will be sealed with silicon. Also, as for the light diffusion...it will be imperfect - but will be improved over newer re-iterations.

Great, silicon sounds like the best way to seal this. So having the LEDS near the top of the bottle gives the best light? Also I assume people use different shape bottles? (some have a different curve below the neck, and I am looking at the clearance there)

@Mark I think that a light in the middle, below the point at which the Rooftop intersects the bottle, is better. One reason is that all the light will be sent downwards into the roof, rather into the night.

well ok all this are very nice...i opened the files from Specs Solar Panel.stl imported in rhino and soliworks and the dimensions are: 5.91mm x 3.55mm x 0.11mm
Now for the battery.stl which i dont know what exacly is it the dimensions are: 1.22mm x 1.75mm x 0.41mm
Are those the correct numbers????????
thank you.

Hey Everybody! Really happy with the response thus far.... can't wait to see the entries. I updated the specs to include dimensions of the solar panel and the battery ... so that everyone is on the same page!

Thanks to, JF Brandon, Frederik Vollbrecht and Ármin Fendrik for your models, it will save everyone a lot of time.
I have a question for JF Brandon, the solar panel specification for the challenge is rated at 7.5V 220ma, and 4 up to 6, 5mm White LEDs, with no battery voltage specified.
Has anyone actually done the calculations to confirm that 7.5V 220ma is sufficient to efficiently charge the batteries as they will need to be of greater voltage than 7.5V to efficiently drive the LED circuit. I am making an assumption by the size and shape of the battery model that it is a bank of four 1.2 V cells, and using two to give you 9.6V which is on the cusp of being too low !!! But it will work. Also do you need a battery charging circuit PCB as the current, will need to be regulated. And thirdly do you require a LED Driver PCB Design.

I uploaded a entry but it is not in the competition. What can I do about this? Also the number of entries is still zero but already 5 or more entries can be found on grabcad. I think something is wrong with the tagging??

If the LED case will be made from a 3D printing process.... I don't think it will end up transparent. I order 3D printed parts all the time and the issue is the limitation in printing thickness and the materials that are used. I would suggest a modification to the specification so that a small glass test tube be used. Sort of defeats the purpose to add LEDs to allow the "bulb"/bottle to work at light if little or no light is emmitted.

@JF, sir u r asking for a housing for the setup.. but my que is, if we were to provide it for those peoples dey would ve used the setup with the used bottles so instead of making it complex to manufacture(3D print) y cant we design a seup which can house the used bottles...?

@pawan... I think the thinking should go along the lines that there would currently be hundreds or thousands of people who are already using the current 'light-bottle' installment. so these would be most likely the people who would want to adapt the LED installment first. i doubt many would be attracted to the idea of having to re-install the whole thing. but i do agree that for new installments it might be more efficient to implement your idea. well... this is only my opinion...

installing the leds inside is the fastest way to improve the bottles... You can do it in a few steps: current cap off, new assembly inside, solar panel attaching to the roof, and only 1 hole is needed for the switch. You dont have to do complex wiring inside, nor outside, you only have to connect 2 wires, while with the out-of-bottle solutions you need more material to achieve the same level of integrity, which is necessary, for the people who gonna buy this equipment dont always have the necessary knowledge. Of course if we would be allowed to use non-3Dprinted parts, but parts of bottles, etc, then we could probably make the design cheaper to produce, but it will make impossible to standardize the product.

doesn't the cap look like it's glued onto the bottle? cement or grout perhaps? and if it is then is this the 'normal' way it is done? which then begs me to ask if replacing the bottle cap with the new assembly is the way to go?

@Stephen Nyberg we're working with limited resources, as is a common issue in developing countries. Essentially we're experimenting if crowdsourcing engineering and design challenges to come up with novel solutions... so try to work with what we got. @HUSSAM it maybe a better component, but it may be more expensive ... if we can source them locally, im all for it... but for the meantime, work with what we got!

Good Idea HUSSAM KAMEL, using straw hat leds
and also from Stephen Nyberg using Cree power leds another good piece of info. But JF Brandon has suggested we should use the existing specified led which is fair comment. So modiffy the existing specified part and carefully place a vee cut or two vee cuts across the dome of the led with a file or put a dimple cut in the centre. this will also increase the spread of light . It may be a bit primitive, but if you are on a desert island, with a box of whatever you can scavenge, you will find a solution lol.

Thanks Stephen. Guess you are going to be the "awesome" one :)
I think we don't have to worry much about roof types and stuff like that because people there are probably using whatever type of material they can find to cover their houses.
As I understood the point is to build casing's for solar cell and led's that are waterproof and the rest is someone else's problem...
Correct me if I'm wrong, Brandon. Cause then I'll pay more attention to how the whole thing is fixed to the roof...

I know, don't think I ment anything wrong with my comment. I was talking in general cause I saw that people are talking about universal roofing metod and there are some models that incorporate roof shape in the casing itself and we can't know for certain the exact shape of the roof...
I do thank you for your roof panel, I already added it to my assembly :)

@Drazen I think we're going to figure out the roof fixture later .... we'll be coming to GC Community in the future for solutions :)
@teigan tell us how that works out... but don't expect us to come by your house for dinner if you invite us.

If you use x 4 Leds ,you wont need shunting resistors at this voltage . I will up load a circuit diagram of how to connect the leds without resistors and with current limiting to LED Light Bottle Design . The batteries could be charged directly from the solar panel, i will upload a pdf explaining how, but I wouldnt recommend it though, charger circuit diagram at Solar Charger PCB.
Please feel free to use these in your design

@JF Brandon, my assembly has a lot of parts that are not going to be printed such as the LED's and bolts and such, do you still want the STL files of these parts included or just the part that are going to be printed?

It is cool to see how so many engineers can come up with so many different solution to one simple problem and even how they use similar ideas in completely different ways! I am choosing the correct carrier path, that is for sure!

Hi everyone, I see that a most of you are designing for a specific corrugated roof panel size, how do you know which panel size these people use? I think they use whatever they can find, so I'm not designing for any panel size, they will just fix the bottle tje way they've been doing it. ;)

Yeah I saw that too... I have seen some buildings like these in bangkok, there are no specifications. I dont think its a good idea to do additional cuts on those roofs either, since they are not really stable, and you need more insulation then. And a last though: I dont think these people want to remove their applied bottles, and re-apply them, just for a lightbulb.

One thing I keep on seeing is integrated designs. That's not really a good idea. As we've been talking about on the comments: Not all roofs are made the same, and the fitting for the roof might be different depending on location. My advice is to design the case for the panel/battery system as SEPARATE from the bottle/roof fitting. One great reason is that we can place it in the optimal orientation to collect the maximum amount of sunlight. So keep that in mind everyone!

I'm not an electrician so I have a question - How is everyone attaching the solar panel? Are you just "gluing" it in to the base with silicone? if the bottom of the solar panel is exposed to the air/elements, could you just apply silicon sealer over the points after the wires are soldered to it?

i guess i'll play along for fun. but i just did the math, and you'll only get about 2 hours of light at optimum conditions, assuming you get full sun for 12 hours and batteries are new. what you are all naively assuming is that LEDs are efficient at 100% duty cycle. In fact they like to be off half the time, and blinking faster than you can perceive. you'll get longer component life and longer light at a reduced duty cycle. your circuit should have a driver circuit and not be directly wiring the LED to the power source. at very least, you should have a resisistor in the circuit to protect the LED. i really didn't want to type all this, and hoped someone else would do the unleasant task of spoiling your little fantasy world. bad news is you'll all need to leave room for a circuit board either in the battery case or the cap. good news is you can have longer light at a reduced intensity, with adjustable dimming a bonus.

Hi teigan just to bounce something back on your comment
1. If the LED’s are rated with a forward voltage of say 3 to 4 V (which is norm for white LED, s) and are connected in series x4, the supply voltage will need to be min 12V. No shunt resistance required - each led will be drawing around 30ma with a voltage drop of around 3V which is well within specification .If you increase the number of LED’s to say x6 the voltage will need to obviously be higher. (Quoting George Ohm) Also to achieve max lumen output the current may need to be higher depending on the LED specification used.
2. Charge current will need to be 10% min of your battery capacity (2200ah therefore I=220ma) to reduce the charge time, this current will need to be higher. Discharge rate depends on the C-rate of the battery, I am not going to get into that one  (Quoting Charles Augustine de Coulomb)
3. To stop you’re on/ off and flickering LED’s the system needs some form of current regulation to keep a constant output.
Did the math and the simulations
Would be interested in seeing your math in black and white to fortify your comments why don’t you upload it as an entry.
Yours Naively
Alan

i was running 3V and you are wrong about the LED being able to run at 3V without current limiting. you will burn it out the gate prematurely. you shouldn't be running an LED in a manufactured product over 2.1V unless you have a regulated power supply which we don't. also, you should be running 1800mah batteries since that is the best economy today. besides, you can't possibly ever charge 4 2100mah batteries to capacity with the solar cell specified. with all that, and a minimum 120ohm resistor limiting current, you will be lucky to pull 2 hours of light. and you will be dimmer toward the end.

hey everyone. after my own preliminary design stage, i've surmised your product is misguided. with cheap mini flashlights already being mass produced, why fuss with 3D printing anything other than an adaptor bottlecap? you can buy a maglite 2AA mini flashlight with a regulated switching power supply circuit for $4 retail(cheaper in quantity). we can attach wires to the battery leads for charging. 3D printing is expensive. why try to compete with mass production?

so the big question is: will i be disqualified, if my bottle light makes use of an efficient inexpensive readily available product? i'll be getting 40 lumens for 8+ hours on only 2 batteries and 1 bulb, thanks to a built in modulation circuit and a fitted reflector. and i won't need a separate battery case. the flashlight sits atop the bottlecap. i'll use a solid semitransparent cylinder to transmit the light to the center of the bottle. we can even make an assortment of caps for various brand flashlights. awaiting your reply grabcad, before proceeding.

also occurred to me we should be running nicads or niMH batteries with full charges and discharges to protect battery life. so it would be better for all you people running 4 batteries to draw current from only two at a time, while the idle ones charge. simplest way to do this would be to have two battery cases. one for the bottle and one for the charger. this way, you could move the solar charger during the day for best sun angle. and there is no reason to have anything on the roof. the batteries can be swapped indoors as needed.

As for the battery conversation - 3.3V LED with 20mA. 4 in series still need 3.3V (or close to) while pulling 80mA. Two 3.6V NimH battery packs in series pump out 1600 mA. With a small resistor (3-12 ohms...maybe none) it pushes enough light for an extended period of time.

I realized now that I made a mistake by putting my NiMh in parallel, it makes charging more difficult. i will have to make some adjustments to the winning design down the road.... i've seen a few schematics for charge controllers - very cool. might incorporate those into the design ....

ok. i was just being practical. why manufactue something from scratch when you can do the job better and cheaper by adapting existing readily available product, i was not suggesting a product from a store. i was suggesting we manufacture an adaptor or two which creates a new use for something very common. this is a real world solution that actually will help people. but if that is not your priority, then i understand and will comply with your rules.

a charge controller is not needed for such a small trickle charge. you can use a simple blocking diode to keep the battery from discharging back to the solar cell when there is no sun. adding a full featured charge controller will constantly rob you of precious milliamps lost as heat. contrary to what alan baird says, you will need a resistor. an LED is a diode, and thus is not linear. the resistor is not only for burnout protection, but also for level performance. you will only need one resistor in the circuit to protect all your LEDs. you have some very basic misconceptions about LEDs. you don't run a 3.3V LED at anywhere near 3.3V in a professional product. best practice is to run it at just over threshold current, with the exception of when you blink the LED rapidly with pulse width modulation, which is what the mass produced flashlights do. the LED is only on a 10th of the time and thus never overheats , allowing for full voltage.

Tiegan
You are obviously an expert in the design and construction of LED circuitry and I appreciate your input. Problem is you keep changing your mind with “charge control” and then “no charge control” and just a blocking diode. But earlier you were talking about full charge and discharge of the batteries to prolong the life of the batteries. I would fit a blocking diode in circuit as a standard precaution anyway, in addition to the blocking diode which will be built into the solar panel and I would definitely suggest using some form of charging circuit to control the charge rate and to protect the batteries and to shut down the charger when the correct charge has been reached.
If you look at Led Driver Board you will see that there is a resistor and a regulator in circuit to drive the leds, it works well as I’ve made one before! It may not be to industry standards but I don’t know what the industry standard is for a manufactured product of this kind.
All I am doing is trying to help these guys find a solution, and I am always open to criticism as long as it is constructive .
Alan

unlike you, i don't use "appeal to authority" as the rhetoric to support my claims. that is a logical fallacy. what difference does it make whether i am a brain surgeon or an icecream salesman? my facts can stand for themselves. i never once said you need charge control. read more carefully, and don't be so quick to dismiss others due to your seniority . i said we should manually run the batteries to full discharge. and manually swap between battery pairs. i never mention any active electronic monitoring. simple as possible is always better. the solar cell in question is ridiculously underspec. you can't overcharge or even fully charge the battery if you use the bottlelight regularly. do you seriously think the solar cell will be outputing as advertised? you would need to be changing the angle every 5 minutes, assuming no clouds or shadows. and if you plan a long period of disuse, you wouldn't want the solar cell up on the roof UV degrading for nothing. best to cover it.

i just looked at your model alan. and if that is indeed a power regulator, then why also have the resisistor protection. use one or the other and not both. the extra resistor would just generate heat and lessen your light time. if i were allowed to use an existing circuit off a mass produced flashlight, it would take up way less space and consume far less current than anything we at grabcad community could design or build. it is silly not to use a flashlight in the project. for the same reasons we aren't designing and 3D printing proprietary batteries. you can already buy it cheaper and better. that is the most important and most basic lesson everyone should learn about rapid prototyping/manufacturing.

but teigan... one thing you might have misunderstood. i think the reason they are using 3d printing is because the winning design will be utilized as part of a project for the 3D4D challenge (www.3d4dchallenge.org) so they HAVE to 3d print it.

yes i understand that, and i would have 3D printed the bottle cap as well as a new endcap for the flashlight to accomodate the modified wiring. my aim was to gain functionality at less cost by incorporating a ready made miniaturized circuit as well as the reflector, LED, mount, and battery case. it still would have been a design challenge to harmoniously unite everything for optimal use.

IMPORTANT: the 5mm LED model file being shared is wrong. someone apparently misread the provided blueprint. DO NOT TAKE REFERENCE POINTS OFF THIS MODEL UNTIL CORRECTING.
if you are using the IGS or STP like i am, then don't use the file at all. i hope i saved someone else from wasting time like i did. people are trying too hard to be "awesome", and not trying hard enough to be competent.

it is the one called 5mm-LED. i discovered the most obvious measurement is wrong, and who knows what else. a 5mm LED should be 5mm diameter. given the circumstances, my ironic attitude is hardly inappropriate.

my entry isn't showing up either. how many hours does it normally take? i didn't have time to model all the electronics or mechanical parts i had intended. so i titled the entry, part 1 of 2. it really is only half done if i'm honest with myself. the real artistry happens in the details.

Challenge is over! Looking through all the entries now! Wow there's a lot of good stuff here - this is going to be very difficult. A good thing, but also a bad thing. Oh and to those whose entry didn't make it in because the bugs, we have em and you're on the list.

it is greatthat you are willing to comment 50+ entries. perhaps to get the most reurn on your time, you should give the feedback in two phases. first you can ask us each a few questions about our concept, needing clarification. then we can answer with a comment or upload drawings/renderings if needed. give us a set time limit for response. then you can give final comments with the benefit of a conversational exchange.

Teigan, I think you are misinterpreting my tone here. All I was trying to say was JF has a lot of entries to through and if he has to tell everyone how to make their model the way he wants it and needs clarification forme each model. He will ever get this challenge judged. Also, if a dimension in one of my models is wrong, please tell me so I can fix it. Don't just say it screwed up and insinuate I'm an idiot who thinks too highly of myself. I think the led I drew in solidworks is correct. If I messed up a dimension I wold like to know what one or if I messed it up when converting it I would like to fix it. I could easily be misinterpreting your tone too but you seem a bit hostile. I am sorry if I offended or provided files that were incorrect.

nobody suggested anyone should remake their model. a selected cross section view may be all that is required. and that potentially saves JF the time of opening the model and creating the view.

and i already stated which dimension is wrong in the LED file. you misread the LED diameter for the lip diameter, even though both are clearly called out in the supplied print. i blame the misguided incentive given to be "awesome". this only leads to more junk we must all sift and filter though in order to find anything useful.

@JF Brandon, Well done at looking at every entry and leaving a comment on each. This was no small feat and I think everyone who entered a design appreciates it. Some of the challenges go so long with no word and in the end you are not even sure your design was looked at or considered. Thanks for all your effort and I think we all look forward to hearing your decision.

@teigan, GrabCAD is a community for sharing and learning between engineers and designers. the dimensions for my LED for led light bottle design challenge are correct as the lip should be 5.8mm according to the provided drawings. I don't think anyone who made a file for use with this challenge was trying to produce junk files just to get an awesome award and I would bet if you could provide the link to the LED with the incorrect dimension or leave a comment like "hey, I think you may have misread the drawing as your dimension for the lip of your LED is incorrect, it should be 5.8mm instead of 5.8mc." I am sure the engineer would thank you for finding their error and do their best to remedy the error and everyone would benefit.

We all want to win :) It's nice when your work is appreciated...
I guess it's not so hard to decide. In these 58 applications there are at least 6-7 parts for challenge, 7-8 with panel above bottle, 5-6 that are not finished, one sketch, probably 10 are not printable etc. Maybe 10 designs are in "final round", at least that's my pov.
Remember grab bot...Or still running 3D printing event... Now that's a whole lot of applications :)

Even if it is out of 10, choosing 2 of the 10 would be a hard task. I'm glad I'm not the one doing it. Also, has anyone noticed... I think JF must be tired because I have not seen a new blog in a little while. ;)

@Stephen Thanks. Yes I've been extremely slammed with work - no time to write a solid blog entry. Yet there's plenty coming! And I'm just trying to set a precedent for everyone who runs design challenges - I'd like everyone to receive at least some sort of comment about their work. You put in the effort to design, i should put in the same 'sweat equity'.... I'm throughly convinced that everyone at least deserves a pint on my behalf :P .....

I would love to but I have an exam today and Brandon said that results are coming soon so there is no time. Maybe after it's finished if I have time. It would be nice to put like 10 of them together so others can really see the effort that we did....

First competition entry for me and I appreciate the feedback JF. We all put in many hours to do this and it's good to feel someone has had a decent look at what we've sweated over. If I ever get to Vancouver again (this time with my mountain bike :) ) I will take you up on that pint! Thanks to the guys who modelled up the parts too. Cheers!

Hi JF BrandonReally appreciate the feedback on the designs, makes all the difference to know that you have taken the time to do this. I think everyone will feel they have achieved something win or lose, thanks to the consideration you have given to every entry. Good luck in the 3D4D challenge and keep us updated on how things are going.

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